1. Field of the Invention
This invention relates to a method for preparing symmetrical azines as well as mixtures containing symmetrical and unsymmetrical azines.
2. Description of the Prior Art
Aldehydes are known to react with ammonia in a complex manner giving rise to various addition, condensation or polymerization products (see for example, The Chemistry of the Carbon-Nitrogen Bond, S. Patai, Interscience, London, 1970, page 67) or with hydrogen peroxide to form unstable peroxide products and to provide peroxide products upon reaction with ammonia and hydrogen peroxide (see for example, J. Chem. Soc. 1969, C, p. 2678).
Moreover, it is known that ammonia, a ketone and hydrogen peroxide react together to produce aminoperoxides (see for example, J. Chem. Soc. 1969, C, p. 2663) and in the presence of tungstic or molybdic acid as catalyst, can lead to formation of an oxime (see for example, J. Gen. Chem. (U.S.S.R.) 1960, 30 p. 1635).
A method for preparing azines comprising the oxidation of ammonia in the presence of a ketone or aldehyde by means of an oxidizing medium of hydrogen peroxide and cyanogen or a nitrile, the latter being converted to the corresponding amide during the reaction, is fully disclosed in commonly assigned pending U.S. application Ser. No. 152,413, filed June 11, 1971.
Still another method for preparing azines comprises reacting ammonia, a carbonyl compound and hydrogen peroxide under appropriate conditions in the presence of a catalytic quantity of certain salts. This method is fully disclosed in commonly assigned pending U.S. application Ser. No. 267,921, filed June 30, 1972.